Frank l



Patented Aug. 25, 1925.

UNITED STATES PATENT OFFICE. a

FRANK L. REMLEIN, or PENNS eitovn, NEW JERSEY, nssxenon T0 E. I. no ron'r DE NEMO'URS & COMPANY, OF WILMINGTON,

WARE.

DELAWARE, A CORPORATION OF DELA- DYEING sULmr R COLORS ON SILK.

No Drawing.

To all whom it may concern:

Be it known that I, FRANK L. REMLEIN, a citizen of the United States, and a resident of lenns Grove, in the county of Salem and State of New Jersey, have invented certain new and useful Dyeing Sulphur Colors on Silk, of which the following is a specification.

This invention relates to dyeing sulphur colors on silk, and comprises a procedure whereby the dyeing of silk by sulphur colors may be satisfactorily accomplished, the color going onto the silk evenly and yet damage to the fibre being avoided. With the present process, whichiis applicable to all sulphur colors, there is no premature oxidation during the dyeing, particularly level and vivid shades are produced, there is no loss in tensile strength or brilliance of the silk, the characteristic soft feel of the silk is not injured, and the fibres will not rise on the yarn in dyeing and will not show the flutliness which, in the silk industry, is known as whiskers. It is the object of the invention to provide a process of the character indicated.

Heretofore, the procedurehas been to new tralize the excess alkali produced by dissolving the dyestufl' in sodium sulphide,=with sodium bisulphite until the dye bath was only feebly alkaline, as tested by phenolphthalein paper which, when the bath had the right alkalinity, showeda rose and not a cherry red. The difficulty has been, however, that if the alkalinity was sufiiciently reduced to save the fibre, the color wenton very unevenly and in some cases hardly at all; while, on the other hand, if the bath were sufliciently alkaline-to properly keep the color in'solution, it Was too alkaline for the fibre and damaged it. I have devised a process by which the difficulties indicated are avoided.

According to the present invention, sodium hydrosulphite is used with the sodium bisulphite, instead of using bisulphite only, to reduce the alkalinity, and also, further departing from previous practice in dyeing sulphur. colorso-n silk, there is added to the bath a protective colloid, as,. for example, the product obtained by treating gum silk with marseilles soap and variousl called bast soap, gum soap,.and boiled-o liquor, another example being cellulose sulphite ably tion of ten Application filed November 5, 1924. SeriaI No. 747,987.

pitch, that is, the pitch from the waste liquor of sulphite wood pulp .manufacture. The ratio of hydrosulphite to bisulphite may be substantially from. 15:85 to 1:1, preferto the bath may be substantially from 3 :400 to 1:20 preferably 1 :50, and, indeed, a great- 1-:3. The ratio of gum or hast soap or proportionof soap than 1 :20 can be used,

but without particular advantage.

The hydrosulphite serves satisfactorily as a reducing'agent in a substantially neutral bath, thus providing for proper dyeing action even though the bath be substantially neutral, as necessary for preservation of the fibres. The protective colloid acts as a preservative of the bath, preventing coaguaction as soap might have, if used in dyeing with acid or basic dyes, to act upon the fibres to facilitate the. saturation thereof; for in the present case the colloid functions with respect to the bath and is used for its effects thereon.

- To illustrate practice in accordance with the invention, but not in restriction of the same, I give the following, it being understood, of course, that the various details, as to temperatures, mechanical operations, and the like, may be varied to suit particular circumstances and are given primarily to ive fullness to the example, rather than as lndicating that the primary features of the invent-ion are restricted to the specific directions given.

For dyeing 100 lbsof silk, make a solu- (10) lbs. immedial yellow D (Schultz #710), a sulphur d estufi", in the usual manner, with ten (10) bs. of sodium sulphide concentrated, that is, chip sulphide.

To the liquonthus produced add a mixture of 7 5 pts., by weight, sodium bisulphite;-25 pts, by weight, sodium hydrosulphite, preferably in solution, in a small quantity of cold Water, until the bath becomes but slightly alkaline, giving only a pink and not a red when tested with phenolphthalein pa- Raise the temperature of the dye bath to F. and at that temperature enter the changes in the procedure just stated are called for, except, instead of m soap is used an amount of pitch subs antially between .5 oz. to 5 oz., preferably 1 oz. per gallon of the liquor, though, as in the case of the soap, the given maximum may be exceeded. It is to be noted that the protective colloidis advantageous even though the alkalinity of the bath be reduced without the use of hydrosulphite.

I claim:

1. In dyeing a sulphur color on silk, the steps of reducing the alkalinity of the dye bath wtih sodiium hydrosulpliite and sodiulm bisulphite,- and adding a protective collOl I 2. In dyeing a sulphur color on silk, the steps of reducing the alkalinity of the dye bath with sodium hydrosulphite and sodium bisulphite in a who substantially between 115 385 to 1:1, and adding a protective col- 3. In dyeing a sulphur color on silk, the

steps of reducing the alkalinity of the dye bath. with sodium hydrosulphite and sodium bisulphite in substantially the ratio 1' :3, and adding a protective colloid.

4. In dyein a sulphur color on silk, the steps of reducing the alkalinity of thedye bath with sodium hydrosulphite and sodium bisulphite, and adding gum soap in an amount, relative to the bath, substantially between the ratios 3:400 and 1:20.

5. In dyeing a sulphur color on silk, the ste s of reducing the alkalinity of the dye bat with sodium h drosulphite and sodium bisulphite, and a ding gum soap in an amount, relative to the bath, ubstantially in the ratio 1 :50.

steps of reducing the alkalinity of the dye bath, and adding a protective colloid.

In testimony whereof I aflix my signature.

' FRANK L. REMLEIN.

7. In dyeing a sulphur color on silk, the 

